Variations in the Branching Pattern of the Radial Nerve Branches to Triceps Brachii Muscle

Abstract

Introduction: The axillary nerve arises from the posterior cord of the brachial plexus and supplies the deltoid and teres minor muscles. Axillary nerve injuries lead to abduction and external rotation weakness. In such cases, branches to the heads of triceps brachii muscle have been transferred to the axillary nerve to establish reinnervation of the deltoid muscle. In addition, the triceps nerve branches can be nerve recipients to reinstitute elbow extension. Aim: To study the different branching patterns of the radial nerve branches to triceps brachii muscle. Materials and Methods: Twenty eight upper limbs from adult cadavers were dissected to record variations in the branching pattern of the radial nerve branches to triceps brachii. Results: The branching patterns seen were types A 1 (3.6%), B1 (1st pattern) 1 (3.6%), B2 (2nd pattern) 1 (3.6%), and C3 22 (78.6%). Two new patterns observed were: type B2 (6th pattern) 1 (3.6%) and type D (2nd pattern) 2 (7.1%). The long head had single innervation in 89.3% cases and the lateral and medial heads had dual innervation in 10.7% and 7.1% cases respectively. Conclusion: The knowledge of the different branching patterns that are present will help surgeons to identify the most suitable radial nerve branch to triceps brachii that can be used for nerve transfer to restore the motor function of the deltoid muscle or to reanimate the triceps brachii muscle.

Keywords

• axillary nerve
• nerve transfer
• pattern of branching